Adjustable in-line valve for sterile fluids

ABSTRACT

A sterile intravenous flow valve includes in-line valve mechanism which is maintained sterile in all of its positions. The valve also includes an adjustment member and a locking mechanism for selectively locking the adjustment member in place to thereby assure accurate flow rate settings. Sterility is achieved by providing a sealed chamber formed by a snap-fit engagement between the adjustment member and the main body member of the valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part application of ourco-pending U.S. patent application Ser. No. 168,722, filed July 14,1980, now U.S. Pat. No. 4,332,369 and entitled "Adjustable In-LineIntravenous Valve With Locking Mechanism". That patent is expresslyincorporated herein, in its entirety, by reference.

TECHNICAL FIELD

The present invention relates to control valves in systems forparenteral fluid infusion. More specifically, the present inventionrelates to a valve which, although simple and inexpensive tomanufacture, permits accurate and reliable adjustable settings ofintravenous liquid flow rate.

BACKGROUND OF THE INVENTION

In administering intravenous fluids to a patient, control of flow rateis critical. If the amount of administered fluid delivered in a givenperiod of time varies considerably from the prescribed dosage rate, theresults can be of serious consequence and are often fatal. The mostcommon types of adjustable flow control used today is a clamp devicewhich pinches the IV (intravenous) tubing by an adjustable amount. Ithas been well documented in the medical literature (see "Flow RateMaintenance and Output Intravenous Fluid Test Sets", Demorouelle, etal., American Journal of Hospital Pharmacy, Vol. 32, pages 177-185,February 1975; and "Regulatory Intravenous Fluid Flow: Controller versusClamps", Ziser, et al., American Journal of Hospital Pharmacy, Vol. 36,pages 1090-1094, August 1979) that such clamps are unable to maintainconstant flow rates for any reasonable period of time. The main cause ofthe problem in this regard is "creep", a phenomeon wherein the plastictubing diameter, when under stress, continues to change. In addition,the settings of these prior art IV clamps are accessible to curiouspatients and susceptible to variation upon movement by the patient.Thus, while adjustable IV clamps are very inexpensive, they represent aconsiderable sacrifice when it comes to maintaining accurate dosagerates.

On the other end of the cost spectrum, the prior art contains automaticsystems for precisely maintaining selectable IV flow rates. Thesesystems are generally made up of electrical pumps, sensors andcontrollers and, for most applications, are prohibitvely expensive. As aconsequence, it is estimated that sales of such systems comprise lessthan ten percent (10%) of the available market, whereas the much lessaccurate but inexpensive adjustable clamps account for substantially allother sales.

Still another approach to adjustable IV flow control is in the in-linevalve characterized by a valving mechanism which is adjustably inserteddirectly into the flow path of the IV fluid. Examples of in-line IVvalves may be found in U.S. Pat. Nos. 3,880,401 (Waltse); 4,079,737(Miller); 3,877,428 (Seagle, et al.) and 3,868,973 (Bierman, et al.).Such in-line valves tend to be more accurate than the adjustable clampand far less expensive than the automatic control system. However, suchin-line valves have not obtained a meaningful share of the relevantmarket for two (2) primary reasons. First, the in-line valves aresufficiently more complex and expensive to manufacture than the clampvalves as to make comparative cost an important factor to the user.Second, although not subject to the "creep" pehonomenon, the in-linevalve is still subject to twiddling by a curious patient and toinadvertent setting variation during patient movement or inadvertentmanipulation by health care personnel.

Valves for use in controlling administration of intravenous fluid mustnot introduce contamination of that fluid. In the case of in-linevalves, this means that the valving mechanism must remain sterile in allof its adjustable positions. While sterility of a valving mechanism canbe readily achieved for an in-line adjustable valve, the resulting valveis usually quite expensive and not readily suitable for a throw-awaydevice.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide aninexpensive device for controlling IV flow rate which provides anaccurate and maintainable setting and which is not subject toinadvertent setting variation. It is a further object of the presentinvention to provide a device of the type described wherein settingchanges by curious patients are considerably minimized. It is stillanother object of the present invention to provide an in-line valvewherein the valving mechanism remains sterile and does not contaminatethe controlled fluid.

In accordance with the present invention, and inexpensively fabricatedIV control valve includes an elongated body member having a longitudinalbore passage defined therethrough and adapted for connection in an IVline. A sluice gate type of valve is adjustably positioned in the borepassage by means of a bolt which threadably engages a bore in the handleand is controlled by an adjustment knob. The adjustment knob ispositioned to be easily turned between the user's thumb and forefingerwhen the member is grasped in the user's palm. A brake lock, preferablyformed as an integral part of the handle member, is arranged to snapinto a locking position, wherein a brake surface is urged against theadjustment knob to prevent movement of the knob and maintain a constantvalve setting. Other forms of valve locking may be used.

Sterility is achieved in one embodiment by providing a sealed chamberfor the gate member and threaded bolt by a snap-fit engagement betweenthe adjustment member and the main body of the valve. In thisembodiment, the threaded bolt remains longitudinally stationary butthreadedly engages the gate member which is movably positioned in thebore passage as the threaded bolt is rotated.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the present invention will become more clear whentaken in conjunction with the drawings, wherein:

FIG. 1 is a view in perspective of the valve and locking mechanism ofthe present invention;

FIG. 2 is a plan view in section of the valve and locking mechanism ofFIG. 1;

FIG. 3 is a view in section taken along lines 3--3 of FIG. 2;

FIG. 4 is a view in section taken along lines 4--4 of FIG. 2;

FIG. 5 is a view similar to FIG. 4 of a different locking mechanismsuitable for use in the present invention;

FIG. 6 is an exploded view of another valve embodiment of the presentinvention;

FIG. 7 is a view in longitudinal section of the valve of FIG. 6; and

FIG. 8 is a view in section along lines 8--8 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring more specifically to the drawings, the valve of the presentinvention includes an elongated body member generally designated by thereference numberal 10. Body member 10 and other valve parts describedbelow can be made from plastic polymers, nylon, teflon, stainless steel,rubber, etc. Body member 10 should be somewhat longer than the width ofan average adult palm and, in one embodiment, is approximately four andone-half (41/2) inches in length. The thickness of the thickest part ofthat embodiment is approximately one and one-quarter (11/4) inches. Itshould be noted that these dimensions are by way of example only andthat neither the dimensions nor the exact contours of the device asillustrated, are limiting features of the present invention. Body member10 is sub-divided lengthwise into two (2) sections, a handle section 11and a control section 12. Handle section 11 may be longitudinallyribbed, as shown, to facilitate grasping of that section withoutrotation in the palm of a user. Control section 12 is described ingreater detail below.

A bore passage 13 extends longitudinally through body member 10 andterminates in respective nipples of projections 14, 15 at opposite endsof the body member. These nipples or projections are adapted to receiveends of IV tubing 40, 41 so that the valve may be inserted directly intoan IV line. Of course, other convention means of engaging IV tubing maybe employed, the important feature being that bore passage 13 isdisposed in series in the IV line.

The control section 12 of body member 10 includes a slot 16 extendinglongitudinally through most of the control section length from the endof the body member in which the control section is located. Slot 16extends entirely through the thickness of the control section 12 so thatthe slot is open at both sides and at one end. A transverse threadedcylindrical bore 17 extends radially from bore passage 13 intocommunication with slot 16. Across slot 16 from the termination of bore17, there is defined a cylindrical recess 18 which is coaxially alignedwith bore 17 but smaller in diameter.

A control member 20 includes adjustment knob 21 in the form of a flatcircular disc. From one side of the center of knob 21 there extends aretainer pin 22 adapted to be received in recess 18. An adjustment pin23, threaded to engage bore 17, extends perpendicularly from the centerof the opposite side of knob 21. Pins 22 and 23 are coaxially alignedbut, as is the case with bore 17 and recess 18, adjustment pin 23 has alarger diameter than retainer pin 22. A gate member 24 is journaled inthe end of adjustment pin 23 remote from knob 21. Gate member 24 isadapted to move transversely across bore passage 13, in adjustabledegrees of flow blocking relationship, as the adjustment pin rotates inbore 17 due to rotation of adjustment knob 21. A slot 19 is defined inpart of the periphery of bore passage 13 opposite bore 17 and contouredto receive the peripheral portion of gate member 24. The control memberis readily inserted into position, with pin 22 in recess 18 and pin 23in bore 17, by flexibly spreading the opposite walls of slot 16. Thediameter of knob 21 is sufficiently great to permit the knob to projectsomewhat out of the slot 16 to permit access by a user.

The primary feature of the present invention involves a locking member26 which is arranged to maintain adjustment knob 21 in the position towhich it has been set. In the preferred embodiment illustrated, lockingmechanism 26 is formed integrally with body member 10 and is located atthe end of the body member which contains the control section 12. Thelocking member is in the form of a flap 28, secured to the body memberat one side of slot 16 and arranged to pivot about a region or line atwhich it is secured. The other or remote end of the flap includes aprojection 27, adapted to mate with and be retained in a suitablyprovided notch 29 located in the body member on the opposite side ofslot 16 from the pivot region. A brake surface 30 is positioned toproject into slot 16 and bear firmly against the rim of knob 21 whenlocking member 26 is closed (i.e., when projection 27 is engaged innotch 29). To further secure the locking function, the brake surface 30and the rim of knob 21 may be ribbed or knurled, as illustrated in FIG.4, to provide a gear-like mating arrangement.

In use, with locking arrangement 26 open, a nurse or other health carepersonnel grasps handle section 11 across the palm, leaving the controlsection 12 and, in particular knob 21, accessable between the thumb andforefinger. Knob 21 is adjusted until the desired IV flow is achievedthrough IV tubes 40, 41 by viewing the drip rate in a conventionalmanner. When the desired flow rate is achieved, locking mechanism 25 isclosed by snapping projection 27 into notch 29. This forces brakesurface 30 against knob 21 and precludes inadvertent movement of theknob. Moreover, the locking arrangement serves as a psychologicalbarrier to conscious or sub-conscious twiddling of the valve by acurious patient. Since there is no clamping of a plastic tube, there isno "creep" phenomeon and the IV flow rate remains constant.

The locking mechanism need not be a brake type lock of the typedescribed above. For example, as illustrated in FIG. 5, a detect lockarrangement may be employed whereby the rim of knob 21 is provided witha plurality of special recesses 33 and the brake surface 30 is replacedby a projection 34 adapted to be received by whichever recess 33radially faces the projection.

It should also be noted that the in-line valve itself need not be asluice gate type valve but may be a globe valve, butterfly valve, ballvalve, etc., the important point being that the valve adjustment devicecan be selectively locked in place.

The particular valve described herein is advantageous in that it is veryinexpensive to manufacture. The valve includes three (3) parts, namelythe body member 10, control member 20, and gate member 25. If lockingmember 26 is made as a separate piece (whereby it may be pivoted by apin or the like), additional but simple parts are required. However, itis quite simple to make a pivotal locking member integral with the bodymember by using, for example, thin-walled polypropylene at the jointbetween the locking and body members. In either case, the valve issufficiently inexpensive to justify single use disposability withoutsacrificing setting accuracy.

The valve assembly is inserted into an IV line between two tubes 40, 41such as standard polyvinylchloride, flexible Tygon, or like medicalgrade tubing at a convenient level to permit the IV drip chamber to beeasily viewed. The unit may be placed in line by the supplier of thetubing 40, 41 or by a technician under sterile conditions. Tubing clampsmay be provided if the connection is to be made in situ.

Depending upon the specific design of the valve of FIGS. 1-5, it ispossible that the valve will not maintain its sterility. Specifically,gate member 24 which comes into direct contact with the sterileintravenous fluid, may be subjected to a non-sterile environment whenraised into and partially above the threaded bore 17. The intravenousfluid can therefore become contaminated. The valve embodimentillustrated in FIGS. 6 and 7 overcomes this problem by providing asterile chamber in which the threaded pin and gate member reciprocate.This valve embodiment is described below with specific reference toFIGS. 6, 7 and 8, wherein the various elements bear the same referencenumerals employed for similar elements in FIGS. 1-5.

The body or handle section 11, having fluid bore passage 13 definedlongitudinally therethrough, has a slot 51 extending transverselythrough the body member entirely across passage 13. Slot 51 is larger inlength and width than the diameter of bore passage 13. The transversecross-section of slot 51 (i.e., parallel to the longitudinal dimensionof bore 13) is substantially rectangular with rounded ends so that theslot approximates an ellipsoid. The flat sides of the ellipsoid slotcorrespond to walls through which the interrupted segments of borepassage 13 are defined. In other words, the segments of bore 13terminate in flat walls of slot 51. In addition, the depth of slot 51extends below bore 13.

An annular rim 53 formed as an integral part of body member 11, extendsupwardly into slot 16 above slot 51. An annular recess 55 is defined inthe inner walls of rim 53 just below the upper lip of the rim. Thediameter of rim 53 is greater than the length of slot 51 between itsrounded ends.

Control member 20 is provided with an integral annular rim member 57which is concentrically disposed about a short length of threaded pin23. The outer surface of rim 57 is provided with an annular protuberance58 sized to engage recess 55 in a snap-fit engagement which permits rim57 to be rotated within rim 53. The outer diameter of rim 57 issubstantially equal to the inner diameter of rim 53 so that the rimsform a sterile seal when engaged by the snap-fit.

Gate member 59 has a transverse cross-section configuration whichexactly matches that of slot 51. A threaded bore 61 is definedlongitudinally into gate member 59 throughout most of the length of thegate member. The threads of bore 61 mate with the threads of pin 23which is threadedly insertable into bore 61 at variable depths. Gatemember 59 is preferably made of a low friction plastic material so thatit can be moved in slot 51, when snuggly fitted therein, by turning knob21 to vary the length of pin 23 disposed in bore 61. In operation, asterile region is formed by rims 53, 57 so that the threaded pin 23 andgate member 59 are not exposed to contaminates in the ambientenvironment. Gate member 59 is raised or lowered in slot 51 by rotatingknob 21 relative to rim 53. The knob 21 and threaded pin 23 remainlongitudinally or axially fixed due to the snap-fit engagement ofprotuberance 58 in recess 55. On the other hand, gate member 59 isprecluded from rotating within slot 51 by the similar substantiallyrectangular or ellipsoid contours of the slot and gate member. Thus, aspin 23 is rotated, its depth in bore 61 changes to force the gate memberto be raised or lowered in slot 51. The gate member is therefore capableof blocking flow between the two segments of bore 13 for providingcontrolled communication between those segments as it is moved in theslot. This control is continuous and depends upon the depth of insertionof the threaded pin 23 within bore 61.

The knob locking mechanism for the embodiment of FIGS. 6 and 7 issubstantially the same as described in relation to FIGS. 1-5 and istherefore not described in detail herein.

The present invention is not to be limited to the embodiments as hereindescribed and illustrated, for numerous modifications can be made by aperson skilled in the art without detracting from the true spirit andscope of the invention as defined in the appended claims.

We claim:
 1. A valve for controlling fluid flow through intravenoussupply tubing, comprising:a body member having a longitudinal passageextending therethrough and means for connecting said passage in serieswith said intravenous tubing, said body member including a first matingelement; selectively movable valve means, including a valve memberdisposed in said passage, for adjustably blocking the flow through saidpassage by moving said member within said passage, said valving meansincluding a movable actuator for said valve member at least partiallyreceived within said body member and means securing said actuator tosaid body member; locking means formed as an integral part of said bodymember, separate from said actuator and selectively pivotableindependently of said actuator between open and closed positions, saidlocking means including a bearing surface which, in said closedposition, bears against said actuator to prevent inadvertent movement ofsaid valve member, said locking means in said open position being out ofcontact with said actuator to permit movement of said valve member, saidlocking means further including a second mating element which engagessaid first mating element to retain said locking means in said closedposition; and sterile sealing means for preventing exposure of saidvalve member to ambient air when said valve member is partially or fullydisposed outside of said passage.
 2. The valve according to claim 1,wherein said actuator comprises a flat adjustment disc and wherein saidlocking means includes a brake surface which bears firmly against saiddisc in said closed position and is spaced from said disc in said openposition.
 3. The valve according to claim 2, wherein said disc includesa knurled rim and wherein said brake surface is knurled to providegear-like engagement with said knurled rim in said closed position insaid locking means.
 4. The valve according to claims 2 or 3, whereinsaid engagement between said first mating element of said locking meansand the second mating element of said body member is a snap-fitengagement.
 5. The valve according to claim 4, wherein said actuatorcomprises a series of like recesses and wherein said locking meanscomprises a projection for engaging said recesses individually.
 6. Thevalve according to claim 1, wherein said body member and said lockingmeans comprises and integral member, and wherein said valving meanscomprises said valve member and said actuator as its only two parts,whereby said valve is made of only three parts in total.
 7. The valveaccording to claim 1, wherein said actuator comprises a manuallyrotatable member having a threaded adjustment pin depending therefromand rotatable therewith, and wherein said sterile sealing meanscomprises:a first annular rim secured at one end to said rotatablemember and disposed concentrically about at least a portion of thelength of said adjustment pin; a slot defined in said body membertransversely through said passage; a second annular rim secured to saidbody member to provide access to said slot; and means for engaging saidfirst and second annular rims concentrically in a snap-fit sterile sealwhich permits selective relative rotation between the rims.
 8. A valvefor controlling fluid flow through intravenous supply tubing,comprising:a body member having a longitudinal passage extendingtherethrough and means for connecting said passage in series with saidintravenous tubing, said body member having a slot defined transverselythereacross to separate said passage into two segments extending fromopposite sides of said slot; selective movable valving means foradjustably blocking flow between said passage segments, said valvingmeans including a gate member having a threaded bore disposed in saidslot so as to preclude rotation of said gate member in the slot, saidvalving means further comprising a movable actuator for said member anda threaded stem secured to said movable actuator which is threadedlyengageable with said threaded bore; a first annular rim secured to saidactuator concentrically about said stem; a second annular rim secured tosaid body member to provide access to said slot; and means for engagingsaid first and second annular rims concentrically in a snap-fit sterileseal which permits relative rotation between the rims, furthercomprising locking means formed as an integral part of said body member,separate from said actuator and selectively pivotable independently ofsaid actuator between open and closed positions, said locking meansincluding a bearing surface which, in said closed position, bearsagainst said actuator to prevent inadvertent movement of said valvemember, said locking means in said open position being out of contactwith said valve member.
 9. The valve according to claim 8, wherein saidactuator comprises a flat adjustment disc and wherein said locking meansincludes a brake surface which bears firmly against said disc in saidclosed position and is spaced from said disc in said open position. 10.The valve according to claim 8, wherein said body member and saidlocking means comprises an integral member, and wherein said valvingmeans comprises said valve member and said actuator as its only twoparts, whereby said valve is made of only three parts in total.